The primary objectives of this research are (1) to determine standard values for the concentrations of all possible nucleotides in whole blood and the formed elements of blood from normal subjects and (2) to test the hypothesis that specific disease states can be characterized by distinctive alterations in blood nucleotides. The concentrations of nucleotides from a large number of normal subjects will be treated statistically to obtain reliable norms so that nucleotide levels can be used to detect various types of neoplastic and genetic diseases to monitor the progress of the disease and to assess the effect of treatment. The nucleotides, which will include pyridines, flavins, purines, and pyrimidines, will be analyzed by high pressure liquid chromatography (HPLC). A third objective is to optimize conditions for a rapid, sensitive and accurate HPLC quantitative analysis of nucleosides in the presences of their bases, to monitor their concentrations in whole blood and the formed elements of blood and to determine quantitatively their concentrations in plasma. These values will be used in investigations of the role of nucleosides in genetic and neoplastic diseases and to test the hypothesis that nucleosides can be toxic if present in plasma or cells in abnormally high concentrations.